Cable-insulation-piercing crimp tool, terminal, and method of forming

ABSTRACT

An insulated conductor sinuously crimped in a hollow tubular section of a terminal. Crimped indentations of the tubular section are disposed on diametrically opposite sides thereof and axially offset. The sides of the section at the indentations are in electrical contact with the conductor. The insulation is dislodged at the areas of contact and disposed in regions of the tubular section where contact does not occur.

United States Patent Inventors Ian E. Robb Newport Beach, Calif.; Marcy R. Malcolm, Jr., Dassel, Minn. Appl. No. 25,148 Filed Apr. 2, 1970 Patented June 29, 1971 Assignee International Telephone and Telegraph Corporation New York, N.Y.

CABLE-INSULATION-PIERCING CRIMP. TOOL, TERMINAL, AND METHOD OF FORMING 3 Claims, 15 Drawing Figs.

U.S. Cl 174/84 C, 29/628, 29/629, 174/90, 339/97 C, 339/276 T Int. Cl 02g 15/08 Field of Search l74/84.l,

[56] References Cited UNITED STATES PATENTS 2,276,140 3/1942 Andrew et a1. 339/276T 3,182,282 5/1965 Turner 339/97 C FOREIGN PATENTS 863,305 3/1961 Great Britain 174/84 C 3 Primary Examiner-Darrell L. Clay Attorneys-C. Cornell Remsen, Jr., Walter J. Baum, Paul W.

Hemminger, Charles L. Johnson, Jr. and Thomas E. Kristofierson ABSTRACT: An insulated conductor sinuously crimped in a hollow tubular section of a terminal. Crimped indentations of the tubular section are disposed on diametrically opposite sides thereof and axially offset. The sides of the section at the indentations are in electrical contact with the conductor. The insulation is dislodged at the areas of contact and disposed in regions of the tubular section where contact does not occur.

PATENTED JUN29 I97! SHEET 1 BF 7 PATENTEU JUN29 I911 3,590.1 4O

SHEET 3 [IF 7 By 1 M A Home y PATENTEUJUNZSIQTI 3,590,140

' saw u [1F 7 By M A Home y PATENTED JUN29 IEIYI 3,590,14

SHEET 7 OF 7 A Hornvy CABLE-INSULATION-PIERCING CRIME TOOL, TERMINAL, AND METHOD OF FORMING The present application i is a division of US. Pat. No. 3,531,971, based on application Ser. No. 475,326 filed July 26, 1965.

The invention relates to a terminal assembly and, more particularly, to an insulated conductor crimped in a hollow tubular section of a terminal.

The object of the invention is to provide an insulated conductor in the tubular portion of a crimped-type terminal which is formed without removal of the insulation.

The invention comprises an insulated conductor which is sinuously crimped in a hollow tubular section of a terminal. Crimped indentations of the tubular section are disposed on diametrically opposite sides thereof and are axially offset. The sides of the section at the indentations are in electrical contact with the conductor. The insulation is dislodged at the areas of contact and disposed in regions of the tubular section where contact does not occur. Moreover, the opposite sides of the section may be in closer proximity intermediate the indentations than elsewhere. The conductor may be of generally flattened kidney shape at the indentations and in generally flattened dumbbell shape intermediate the indentations. In the drawings:

FIG. I is a side elevation of a crimp tool embodying the crimping mechanism.

FIG. 2 is an enlarged vertical section of the crimping mechanism with an insulated cable inserted in the tubular portion ofthe terminal.

FIG. 3 is a view similar to FIG. 2 with cradle blocks in positioning engagement with the tubular elementofthe terminal.

FIG. 4 is a view similar to FIG. 3 showing a crimping pin advanced against the tubular terminal element.

FIG. 5 is a horizontal section of the crimping mechanism with parts positioned as in FIG. 3.

FIG. 6 is a view similar to FIG. 5 with the vanced as in FIG. 4.

FIG. 7 is a longitudinal section of the terminal showing the insulated cable lodged in the tubular element of the terminal, as seen in FIG. 5.

FIG. 8 is a longitudinal section of the crimped assembly of terminal and cable, as seen in FIG. 6.

FIG. 9 is a cross section taken on the line 9-9 of FIG. 7.

FIG. 10 is a cross section taken on the line 10-10 of FIG. 8.

FIG. 11 is a cross section taken on the line IllI of FIG. 8.

FIG. I2'is a longitudinal section of a second form of terminal and cable assembly prior to crimping, the tubular element having three different diameter bores for more conveniently accepting several different size cables.

FIG. 13 is a view similar to FIG. 12 with a cable crimped in the terminal.

FIG. 14 shows a third form of terminal featuring a modified bore in the tubular element.

FIG. 15 is a view of the form shown in FIG. 14 upon completion ofthe crimping operation.

The device comprises a tool body formed with a recess 2I for retaining a crimping mechanism 22 operated by an actuator bar 23. The actuator bar is shifted forwardly by squeez ing together handles 24 and 25 which operate on the actuator bar through a toggle linkage 26, the handles being normally spread open by a spring 27. Any other suitable and convenient form of handles and linkage or other transmission may be employed by which actuator bar 23 or an equivalent can be advanced and retracted. This bar is slidably mounted in a bore 28 in the body 20.

A plate 30 covers one side of the recess 21, this plate being formed with an elongated slot 31 through which a contact end 32 ofa terminal 33 may extend, but the slot is sufficiently narrow so that the plate functions as a positioning stop for a shoulder 34 on the terminal.

A die member 35 provided with a mounting stud 36 is fixedly secured in the body wall at one end of the recess as by a crimping pins adpin 37 driven through a bore 38. This die member threadedly mounts a plurality of crimping pins 40. These pins are formed with a relatively large diameter central section 41, providing a shoulder 42 at the mounting end, and tips 43 of reduced diameter at the crimping end. These tips 43 are preferably hemispherically rounded as illustrated. The intermediate section 41 of each pin is slidably sustained in a bore 44 in a cradle block 45. Compression springs 46 yieldably separate the die member 35 and the cradle block 45. The die member and block, however, are retained in proper orientation by guide bolts 50 preferably mounted on the die member 35, having enlarged heads 5 I slidably engaging in bores 52 in the cradle block.

A movable die member 55 which may be identical to the die member 35 mounts crimping pins 40 which are identical to those on the opposite side, and a cradle block 56 is associated with the die member 55 in the same manner as on the opposite side of the mechanism. The die member 55 has a stud 57 which by means ofa pin 58 is mounted in the end of the actuator bar 23.

The cradle blocks 45 and 56 are formed with mating semicylindrical channels 59 and 60 for positioning and supporting the external surface of a pot section or tubular element 33a of the terminal 33. The channels 59 and 60 are interrupted by the bores 44 through which the pins 40 advance. Test bores in the block45 are opposite those in the block 56 but are staggered axially of the bore formed by the combined channels 59 and 60. Thus a supporting wall segment 61 is presented opposite each pin 40.

In use a cable C made up ofa conductor 62 covered by insulation 63 is inserted into the tubular element 33a of the terminal. This temporary assembly is then placed between the cradle blocks 45 and 56 in their spread apart relationship as shown in FIG. 2, with the terminal collar 34 placed against the plate 30 for proper registration.

Thereupon the actuator bar 23 is advanced by squeezing the handles 24 and 25 sufficiently so that the cradle block 56 moves toward the cradle block 45, and the tubular element 330 is firmly secured in position in the channels 59 and 60. The cradle block 45 does not move during the initial action of the actuator bar 23 but remains in the position shown in FIGS. 2 and 3 under the influence of the compression springs 46.

Further advancement of the actuator bar 23 by continued and increased pressure on the handles 24 and 25 causes the die member 55 to advance against the yieldable resistance of the springs 46, the springs 46 on both sides of the mechanism becoming compressed and the cradle blocks shifting to the left as seen in FIG. 6. The pin tips 43 then indent the wall ofthe tubular element 33a as shown in FIGS. 4 an 6. These indentations are diametrically opposite and in the same plane, and are offset or staggered as shown. The relatively mutual advance of the two die members 35 and 55 is limited by abutting engagement of the heads 51 of the guide bolts 50. (See FIG. 4.) Preferably each pin advances to approximately the axis of the tubular element.

The indentation in each case is such as to deform the wall of the tubular section inwardly in a dimple configuration. As the channel surface in the cradle block on the opposite side supports the opposite wall, it is obvious that deformation of the cable must occur, and inasmuch as the insulation is softer than the conductor the insulation is dislodged under the advance of the deformed wall which results in metal to metal or electrical conductive contact between the tubular element and the proximate conductor of the cable.

Inasmuch as the indentations on opposite sides are staggered, a sinuous pattern of a centralized portion of the tubular section and of the cable enclosed within it is formed, as particularly shown in FIG. 6. Thus, a permanent and wholly satisfactory mechanical retention of the cable in the terminal is obtained.

As seen in FIG. 10, the tendency in the central region of the crimped dimple is to push the insulation laterally away from the top and bottom sides of the conductor, crowding the insulation into lateral areas, while the conductor part of the cable is somewhat flattened out, the cavity and the deformed cable within it resembling in cross section a crescent moon shape, the conductor itself having a general kidney shape.

In the region intermediate adjacent crimped dimples, a shown in FIG. 11, the tendency is again to push the insulation off of the conductor and to flatten out the conductor into somewhat of a dumbbell shape.

Thus, not only is good electrical contact made between the conductor and the terminal wall but the differing configuration in cross section of the deformed cable as confined in the correspondingly different cross sections of the tubular portion of the terminal member provides a series of mechanical obstructions against withdrawal of the cable from the terminal in addition to the overall sinuous configuration which is a major obstruction to separation.

The illustrations in FIGS. 1--11 have been described as exemplification of a terminal having a tubular or pot section of constant inside diameter in which a cable of only one general outside diameter is crimped with complete satisfaction. In FIGS. !12'-15 modified forms are illustrated wherein, as in FIGS. 12 and 13, three stepped inside diameters 70, 71 and 72 and at least two outside diameters 73 and 74 are displayed; and in FIGS. 14-15 one major inside diameter 75 and a tapering diameter 76 with corresponding outside diameters 77 and 78 are employed. With this construction cables of several sizes may be utilized in conjunction with a single terminal, and while the crimping will occur throughout most of the length of the tubular element, depending upon the number of crimping pins utilized, the progression of the crimped dimples into the cable will be more effective in the immediate area where the cable approximately fits within the bore of the terminal. If forms of the character shown in FIGS. 12-15 are employed it is desirable to modify the semicylindrical channels 59 and 60 so that they conform to the outside diameter of the tubular elements. This will insure that wall support is provided in opposition to the entry force of the crimp pins.

The relative diameter, length and spacing of the crisp pins may be varied. The illustration in the drawings represents a general relationship which has been found satisfactory. There, the axial offset of a pin on one side from the adjacent pin on the opposite side is such that when the pins are fully advanced, as shown in FIG. 6, with the result therein illustrated and confirmed in FIG. 8, the shortest lime between two adjacent opposite pins as exemplified by the line 11-11 in FIG. 8 is slightly less than half the outside diameter of the original tubular element so that the cable will be deformed as illustrated, but the spacing is sufficient so that the cable will not be completely severed, its total cross-sectional area, at least of the conductor, being substantially retained throughout the crimping attachment.

Although we have herein shown and described our invention in what we have conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of our invention, which is not to be limited to the details disclosed herein.

What we claim as new and desire to secure by Letters Patent is:

1. An article of manufacture comprising an insulated conductor sinuously crimped in a hollow tubular section of a terminal, characterized by crimped indentations of the tubular section disposed on diametrically opposite sides thereof and axially offset, the sides of the section at the indentations being in electrical contact with the conductor, the insulation being dislodged at the areas of contact and disposed in regions of the tubular section where contact does not occur.

2. An article of manufacture as defined in claim 1 wherein the opposite sides of the section are in closerproximity intermediate the indentations than elsewhere.

3. An article of manufacture a defined in claim 2 wherein the conductor is in a generally flattened kidney shape at the indentations and in a generally flattened dumbbell shape intermediate the indentations. 

1. An article of manufacture comprising an insulated conductor sinuously crimped in a hollow tubular section of a terminal, characterized by crimped indentations of the tubular section disposed on diametrically opposite sides thereof and axially offset, the sides of the section at the indentations being in electrical contact with the conductor, the insulation being dislodged at the areas of contact and disposed in regions of the tubular section where contact does not occur.
 2. An article of manufacture as defined in claim 1 wherein the opposite sides of the section are in closer proximity intermediate the indentations than elsewhere.
 3. An article of manufacture a defined in claim 2 wherein the conductor is in a generally flattened kidney shape at the indentations and in a generally flattened dumbbell shape intermediate the indentations. 